[PonyORM-list] ponyorm-list Digest, Vol 16, Issue 2

[Bruce Petersen]

Hi Alexander!

Thanks very much for your suggestion (multiple Database objects).  In fact,
after reviewing our product 'straw man' architecture, it became clear we
would want multiple Database objects for a few reasons (including your
suggestion).  This works great for us - our mainstream database objects are
very static (not dynamic).  The use case for our "author" category users
may actually benefit from having their own database in Postgres (which is
what I experimented with to much success).

The more I use Pony, the more I love its simple elegance.

I really appreciate your prompt reply and thoughtful answer.

Best Regards,

Bruce


On Thu, Dec 4, 2014 at 6:00 AM, <ponyorm-list-request at ponyorm.com> wrote:

> Send ponyorm-list mailing list submissions to
>         ponyorm-list at ponyorm.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         /ponyorm-list
> or, via email, send a message with subject or body 'help' to
>         ponyorm-list-request at ponyorm.com
>
> You can reach the person managing the list at
>         ponyorm-list-owner at ponyorm.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of ponyorm-list digest..."
>
>
> Today's Topics:
>
>    1. case sensitive (Goldberg, Arthur P)
>    2. Re: case sensitive (Alexey Malashkevich)
>    3. Re: Entity Creation (Alexander Kozlovsky)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 3 Dec 2014 14:19:35 +0000
> From: "Goldberg, Arthur P" <arthur.p.goldberg at mssm.edu>
> To: Pony Object-Relational Mapper mailing list
>         <ponyorm-list at ponyorm.com>
> Subject: [PonyORM-list] case sensitive
> Message-ID: <9A65CBDB-9CD1-4682-AE41-6FB004AF1385 at mssm.edu>
> Content-Type: text/plain; charset="utf-8"
>
> Hi All
>
> I'd like DBMS string searches to case sensitive. THAT is, if 'A' is in the
> dbms, a search for 'a' shouldn't find it.
> but my DBMS is MySQL (on mac), so it is case insensitive<
> http://dev.mysql.com/doc/refman/5.6/en/case-sensitivity.html>.
>
> thoughts?
>
>
>
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> /ponyorm-list/attachments/20141203/e8df4dbd/attachment-0001.html
> >
>
> ------------------------------
>
> Message: 2
> Date: Thu, 4 Dec 2014 00:58:24 +0400
> From: Alexey Malashkevich <alexeymalashkevich at gmail.com>
> To: Pony Object-Relational Mapper mailing list
>         <ponyorm-list at ponyorm.com>
> Subject: Re: [PonyORM-list] case sensitive
> Message-ID:
>         <CABuFHj45Setyvg1dxSF=
> 7sN3mxiUWpRxmaWfmvacawG+-S_LcQ at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi Arthur,
>
> One of the approaches is to specify the case sensitive collation when you
> create your database.If you use only latin1 charaters, then you can use
> latin1_general_cs collation. If you use utf8 characters in your
> application, then you need to use utf8_bin collation:
>
> CREATE DATABASE db_name
>     [[DEFAULT] COLLATE collation_name]
>
> For example:
>
> CREATE DATABASE test COLLATE latin1_general_cs
>
> In this case all selects will be case sensitive. See more information on
> this here: http://dev.mysql.com/doc/refman/5.0/en/charset-database.html
>
> If you want only one attribute to be case sensitive, you can use the
> sql_type parameter of an attribute when you declare your entities:
>
> class MyEntity(db.Entity):
>     attr1 = Required(str, 200, sql_type='VARCHAR(200) COLLATE
> latin1_general_cs')
>     attr2 = Required(str, 200, sql_type='VARCHAR(200) COLLATE utf8_bin')
>
> In the example above attr1 uses latin1 characters and all selects will be
> case sensitive. attr2 uses utf8 characters and will be case sensitive.
>
> Here you can see all available collations for MySQL
> http://dev.mysql.com/doc/refman/5.0/en/charset-mysql.html
>
> In future we will add the ability to specify collation for attributes this
> way:
>
> class MyEntity(db.Entity):
>     attr1 = Required(str, collate='latin1_general_cs')
>     attr2 = Required(str, collate='utf8_bin')
>
> Regards,
> Alexey
>
>
> On Wed, Dec 3, 2014 at 5:19 PM, Goldberg, Arthur P <
> arthur.p.goldberg at mssm.edu> wrote:
>
> >  Hi All
> >
> >  I'd like DBMS string searches to case sensitive. THAT is, if 'A' is in
> > the dbms, a search for 'a' shouldn't find it.
> > but my DBMS is MySQL (on mac), so it is case insensitive
> > <http://dev.mysql.com/doc/refman/5.6/en/case-sensitivity.html>.
> >
> >  thoughts?
> >
> >
> >
> >
> >
> > _______________________________________________
> > ponyorm-list mailing list
> > ponyorm-list at ponyorm.com
> > /ponyorm-list
> >
> >
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> /ponyorm-list/attachments/20141204/fabbb398/attachment-0001.html
> >
>
> ------------------------------
>
> Message: 3
> Date: Thu, 4 Dec 2014 14:25:52 +0300
> From: Alexander Kozlovsky <alexander.kozlovsky at gmail.com>
> To: Pony Object-Relational Mapper mailing list
>         <ponyorm-list at ponyorm.com>
> Subject: Re: [PonyORM-list] Entity Creation
> Message-ID:
>         <
> CAGM6z1swWT78--AYki+CfEaVcxF6mAux0e_QOi5YFO6krCaUmg at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi Bruce!
>
> > We really require the ability to add an entity to the schema while the
> using application is active.
>
> Currently Pony doesn't allow to change or add entities to Database object
> after the mapping was generated. Theoretically, in the future we can allow
> it, but it will complicate internal architecture. What should we do when in
> multi-threaded application one thread starts a transaction and the other
> thread starts changing database entities? Currently the logic is simple,
> you just create all entities and then start working with them in any
> thread.
>
> > Do you have any suggestions / work-arounds (besides re-initializing the
> Database object)?
>
> If it is possible, could you describe your use-case in more detail? Why
> re-initializing of the Database object is not suitable for you?
>
> Note that you can have several Database objects working with the same
> physical database. For example, you can have one Database object for
> "static" entities which remains the same during your application lifetime,
> and the other Database object for "dynamic" entities which is created
> programmatically. When you list of "dynamic" entities is changed, you can
> do db.disconnect() for previous "dynamic" db object, and then create new db
> object with updated entity definitions. This is the example of how you can
> create entity programmatically:
>
>     from pony import orm
>     from pony.orm.core import EntityMeta
>
>     db = orm.Database()
>
>     attrs = {}
>     attrs['id'] = orm.PrimaryKey(int, auto=True)
>     attrs['name'] = orm.Required(str)
>     attrs['age'] = orm.Required(int)
>
>     Person = EntityMeta('Person', (db.Entity,), attrs)
>
>     db.bind('sqlite', ':memory:')
>     db.generate_mapping(create_tables=True)
>
>     with db_session:
>         p1 = Person(name='John', age=20)
>
> Tell me what do you think about having two Database objects in you
> application
>
>
> Regards,
> Alexander Kozlovsky
>
>
> On Wed, Dec 3, 2014 at 6:46 AM, Bruce Petersen <
> bruce.petersen at ironsafe.com>
> wrote:
>
> > Greetings!
> >
> > I'm seeing great advantages to Pony -- however, perhaps you can help me
> > through one major stumbling block:
> >
> > Our app requires that tables (and their classes) be created on-the-fly.
> > Given my understanding of the lifecycle of entity mappings, it looks like
> > entity mappings really cannot be created dynamically.  That is, it looks
> > like Pony requires that Entities need to be mapped before any using
> > application starts, yes?  Any attempt to sub-class Entity results in an
> > exception once the first generate_mapping is called.
> >
> > We really require the ability to add an entity to the schema while the
> > using application is active.  We've been using SqlAlchemy to create
> models
> > throughout the life of the application -- we were very much looking
> forward
> > to using Pony's awesome features.
> >
> > Do you have any suggestions / work-arounds (besides re-initializing the
> > Database object)?
> >
> > Many  Thanks,
> >
> > Bruce
> >
> >
> >
> >
> >
> > _______________________________________________
> > ponyorm-list mailing list
> > ponyorm-list at ponyorm.com
> > /ponyorm-list
> >
> >
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> /ponyorm-list/attachments/20141204/d4d008b9/attachment-0001.html
> >
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> ponyorm-list mailing list
> ponyorm-list at ponyorm.com
> /ponyorm-list
>
>
> ------------------------------
>
> End of ponyorm-list Digest, Vol 16, Issue 2
> *******************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: </ponyorm-list/attachments/20141204/cb17291c/attachment.html>